title: Condurango-glycoside-A fraction of Gonolobus condurango induces DNA damage associated senescence and apoptosis via ROS-dependent p53 signalling pathway in HeLa cells.
abstract: Gonolobus condurango plant extract is used as an anticancer drug in some traditional systems of medicine including homeopathy, but it apparently lacks any scientific validation. Further, no detailed study is available to suggest whether condurango-glycoside-A (CGA), a major ingredient of condurango serves as a potent anticancer compound. Therefore, we investigated apoptosis-inducing ability of CGA against cervix carcinoma cells (HeLa). β-galactosidase-activity and DNA damage were critically studied at different time points; while induced DNA-damage was observed at 9-12th hours, senescence of cells appeared at a later stage (18th hour after CGA treatment), implicating thereby a possible role of DNA damage in inducing pre-mature cell senescence. Concurrently, the number of cells undergoing apoptosis increased along with increase in reactive oxygen species (ROS) generation. Expression of p53 was also up-regulated, indicating that apoptosis could have been mediated through p53 pathway. DCHFDA (4',6-Diamidino-2-phenylindole dihydrochloride) assay, acridine orange/ethidium bromide staining and annexin V/PI assay results collectively confirmed that apoptosis was induced by increased ROS generation. Reduction in proliferation of cells was further evidenced by the cell cycle arrest at G0/G1 stage. Expression profiles of certain relevant genes and proteins like p53, Akt, Bcl-2, Bax, cytochrome c and caspase 3 also provided evidence of ROS mediated p53 up-regulation and further boost in Bax expression and followed by cytochrome c release and activation of caspase 3. Overall results suggest that CGA initiates ROS generation, promoting up-regulation of p53 expression, thus resulting in apoptosis and pre-mature senescence associated with DNA damage.
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, 741235, India.
authors.forename: Kausik
authors.initials: K
authors.lastname: Bishayee
authors.forename: Avijit
authors.initials: A
authors.lastname: Paul
authors.forename: Samrat
authors.initials: S
authors.lastname: Ghosh
authors.forename: Sourav
authors.initials: S
authors.lastname: Sikdar
authors.forename: Avinaba
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Raktim
authors.initials: R
authors.lastname: Biswas
authors.forename: N
authors.initials: N
authors.lastname: Boujedaini
authors.forename: Anisur Rahman
authors.initials: AR
authors.lastname: Khuda-Bukhsh
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D059447:Cell Cycle Checkpoints / Q000187:drug effects / Q000235:genetics; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D016922:Cellular Senescence / Q000187:drug effects* / Q000235:genetics; D004249:DNA Damage; D016193:G1 Phase / Q000187:drug effects / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D031101:Marsdenia / Q000737:chemistry*; D013058:Mass Spectrometry; D011278:Pregnanes / Q000737:chemistry / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016192:Resting Phase, Cell Cycle / Q000187:drug effects / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D011278:Pregnanes; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; C015758:condurangin; D051057:Proto-Oncogene Proteins c-akt